Apparatus for finishing fibrous material

ABSTRACT

Fibrous material in web or filament form, to be dyed or otherwise chemically treated, is successively passed through a plurality of chambers including a treatment chamber in which it is subjected to the spray of a fluid, a drying chamber which may be subdivided into several compartments, and an intervening reaction chamber in which a controlled amount of moisture is added and which may be preceded by a preconditioning chamber provided with temperature-control means. Air is forcibly circulated, with the aid of a primary blower, from a location near the inlet end of the treatment chamber to a point of the drying chamber remote from the treatment chamber whereby this air passes through the interconnected chambers in counter-current to the treated material. Each chamber may also be provided with an individual secondary air path containing a blower for generating a flow which passes only through that chamber in counterflow to the treated material.

United States Patent Hauser et al.

APPARATUS FOR FINISHING FIBROUS MATERIAL Assignee: Bohler & WeberKG-Maschineniabrik- Augsburg, Hamburg, Germany Filed: Sept. 15, 1969Appl. No.: 871,361

Related US. Application Data Division of Ser. No. 462,167, June 4, 1965,abandoned.

Foreign Application Priority Data June 5, 1964 Switzerland ..7363/64U.S. Cl. 1.68/18- C, 68/18 F, 68/191,

68/20 Int. Cl. ..B05c 3/132, BOSc 9/10, BOSc 9/12 Field of Search..68/l8 R, l8 C, 18 F, 20, 3 R,

68/5 D,5 E, 3 SS, 19.1, 19

References Cited UNITED STATES PATENTS Gruber-Rehenburg et a]. ..68/ l 8X I I l l l 51 May 30, 1972 2,199,233 4/1940 Williams ..68/2O X2,571,494 10/1951 Spooner ..68/20 X FOREIGN PATENTS OR APPLICATIONS1,059,530 11/1953 France ..68/l8 Primary Examiner-William l. PriceAtt0rneyl(arl F. Ross [57] ABSTRACT Fibrous material in web or filamentform, to be dyed or otherwise chemically treated, is successively passedthrough a plurality of chambers including a treatment chamber in whichit is subjected to the spray of a fluid, a drying chamber which may besubdivided into several compartments, and an intervening reactionchamber in which a controlled amount of moisture is added and which maybe preceded by a preconditioning chamber provided withtemperature-control means. Air is forcibly circulated, with the aid of aprimary blower, from a location near the inlet end of the treatmentchamber to a point of the drying chamber remote from the treatmentchamber whereby this air passes through the interconnected chambers incounter-current to the treated material. Each chamber may also beprovided with an individual secondary air path containing a blower forgenerating a flow which passes only through that chamber in counterflowto the treated material.

18 Claims, 5 Drawing Figures HEA r52 l Moan/e5 ass/5oz 8 2zswcr/mrzo-meaalwawiry Patented May 30, 1972 2 Sheets-sheet 2 51 has/ar51? cowaawssp 71 s r24 wag Paul Hauser d fer Pfisfer Hans U- S i HeinzTeuwen Heinrich Furing Johannes H. Sieber INVENTORS.

By To 5 flesiem APPARATUS FOR FINISHING FIBROUS MATERIAL Thisapplication is a Division of Ser. No. 462,167, filed June 4, 1965 andnow abandoned.

Until now it was usual to finish especially woven and knitted textilesand bands of bonded fibers in aqueous media. These complicated workingmethods are all identified by high cost of apparatus and operation.So,-for instance, large quantities of water and high drying energies areusually required. Shrinkage is often observed which after finishing mustbe compensated for. Substantial, costly waste-water problems arise sincesuperfluous unused chemicals have to be separated from the waste water.With some materials, as for instance cellulose acetate, very often inaqueous finishing an uneven fabric appearance results. In dyeing theloss of dyestuff is relatively high. Finally, the finishing processesoften have to be performed one after the other and a single-stagecontinuous finishing is not possible. The complete finishing up to thesaleable textile material is therefore very time-consuming. The resultof this is that a relatively large amount of stock has to be carried inorder to be able to give short-time delivery.

It is the aim of the invention to remove the above-mentioneddisadvantages by a new fabric-treating system.

An apparatus according to the invention, comprises means for thesaturation of the goods with a liquid, as for instance in a paddingmachine, in conjunction with transport arrangements consisting ofrollers or the like for the guiding a web of textile material and arecovery section for volatile condensable substances, the two sectionsbeing interconnected by a forced-circulation path including blowermeans, a condensor and, if necessary, an air heater.

With conventional drying, strips and webs of solvent-wetted materialwould be guided within a housing over several rollers in an up-and-downfashion by means of loops. Via a recovery section air is blown in such asystem in a closed circuit from above into the housing and drawn awayunderneath. This arrangement, however, does not dry textiles evenly andis, therefore, unsuited for finishing, since an uneven deposition ofchemicals would result. Moreover, this continuous heating and cooling ofthe total required air quantity is very expensive with its high rate ofenergy consumption.

The apparatus according to the invention aims at avoiding theabove-mentioned disadvantages and achieves an economical drying processwith the least expense. At the same time in the whole drying zone afavorable and even concentration gradient between the textile materialand the surrounding air for a uniform deposition of the finishingchemicals is achieved.

The treatment chamber of the apparatus according to the invention isfollowed by a drying chamber whose walls surround a section of travelingmaterial moving vertically, the recovery section being connected to thisdrying chamber by the aforementioned path forming a closed circuit witha suction side in the area of the entry of the material into thetreatment chamber and with a high pressure side in the area of the exitof the material from the drying chamber. In a particularly advantageousembodiment of the invention a number of drying chambers are providedwhich are joined with their vertical sides through which the web ofmaterial travels in alternating directions with the aid of reversingrollers or the like. Thus, the drying air flows over the material in acounter-current whereby a progressive enrichment of the air with solventvapors is achieved with a roughly constant concentration gradient.

In a particularly practical version the chambers are formed as adjoiningcompartments within a closed housing subdivided by vertical partitions.

In order to increase the economy of drying and recovery, we prefer tosupplement the recovery section with its primary air circuit through thecascaded treatment and drying chambers by mounting a separate blower orfan, followed by an air heater, in a further, secondary air circuitindividual to each of these chambers. In particular it is desirable thatthe air heater be connected to banks of jets which are on both sides ofthe traveling material with the jets directed against the material. Thusit is no longer necessary to circulate large quantities of air with lowvapor concentrations through the recovery sections. The economy ofcondensation is increased, since the vapor concentration of the airwhich reaches the recovery section via the main air circuit isconsiderably stepped up, because of the rapid continuous circulation ofthe air quantity which is contained in each individual chamber while itis being heated and enriched with solvent vapor. v

These and further features are illustrated by way of example andschematically in the accompanying drawing in which FIG. 1 is, aschematic side view of the apparatus for the finishing of material inweb form in solvent according to the invention;

FIG. 2 is, a schematic side view of a reaction chamber which is precededby a dyeingmachine;

FIGS. 3 and 4 show an arrangement for the preconditioning of acontinuous length of fabric;

FIG. 5 is a diagram of a cleaning and finishing plant.

With the arrangement according to FIG. I the cloth 1 travels through thetreating means 2 which consists of the chassis or liquid-containingtrough 3 and the squeezing rollers 4, and then enters the treatmentchamber 5. Its direction is changed by the rollers 6 and then it passesapproximately in a straight line, yet in alternating directions, througha series of drying chambers 7, 8 and 9 which are situated beside chamber5. The chambers are formed inside the closed housing 11 by dividingwalls or partitions 10.

For the recovery of the solvent in the primary air circuit the fan 12and, on its downstream side, the cooler 13 are arranged. The suctionside of the fan 12 is in turn connected via a duct 15 with an intakeport 15a to the entrance section of chamber 5. The cooler 13 isconnected via a duct 16 with the exit of chamber 8. In this way arecovery circuit is formed in which the drying air passes successively,counter-current to the traveling material, through chambers 8, 7 and 5.If necessary, beyond the cooler 13 a heater 14 may be provided which isonly indicated in dotted lines in the drawing.

The individual chambers 5, 7 and 8 can, as may be seen from theleft-hand section of FIG. 1, be provided with a further fan 17' and anair heater 18 on its downstream side. The fan is connected with itssuction side via a duct 19 to one end of the chamber, so that asecondary air stream travels through the individual chamber in a closedcircuit. The heater 18.may be situated on the suction or on the highpressure side of the fan 17. Preferentially the heater 18 is disposedahead of two sets of air jets 21, lying on both sides of the path offabric 1, through which the material may be treated from both sides withhot air via a conduit 20 with discharge ports 20a, 20b. Such anarrangement can be provided in each one of the chambers. For the sake ofsimplicity, however, this arrangement is shown in FIG. 1 only forchamber 5. By means of the secondary air circuit the air in theindividual chambers is very quickly circulated and thereby constantlywarmed and enriched with solvent gases. The air which is drawn in by fan12 and which is then pressed into cooler 13 has, therefore, aconsiderably higher solvent-vapor concentration than it would havewithout the presence of such a secondary air circuit.

In order to maintain a certain water recovery from the material, a valve23 or 23 of an arrangement which injects steam or water into the circuitis controlled by the hygrometer 22 in the duct 19 which measures thehumidity of the air leaving the chamber. The operation of the valve 23or 23' by means of the hygrometer 22 takes place by a well-knownelectrical system and is therefore indicated only by the dotted line 24.The injection of fine water droplets into the air circuit takes placeadvantageously before the entry of the air into the air heater. Theinjection of steam can also be performed beyond the heater. In this waya certain relative humidity in the individual chambers may be createdand constantly maintained. The water recovery from the material leavingthe drying chambers may alternatively be controlled by arecoverymeasuring device 55 which, by well-known means, is connected tothe steam or water spray valves 23 or 23. An air inlet is shown at 56.

Depending on requirements, several of such drying chambers may bemounted side by side, so that the traveling materia] has to pass oneafter the other. In this arrangement, chambers which are disposed inseries may be connected to a recovery section 12, 13. There can also beseveral recovery sections 12, 13 assigned to a smaller group ofchambers. Through a further chamber 9, following the chambers whichserve for the drying and recovery, fresh air may be drawn with the aidof a fan 26 which is mounted on an activated-carbon recovery stage 25.In a preferred embodiment final compartment 9 of the drying stage has aduct 27 forming an extraction circuit (in direction of the arrow) inorder to recover the last traces of solvent. The individual ducts 20, 27may be provided with branch lines 28 which can be closed or opened andwhich lead into the atmosphere or to an activated-carbon recovery plant.it is further advantageous to have a suction duct 29 connected to thehousing of the treating means which also leads to an activated-carbonrecovery plant.

In order to create particularly favorable conditions for the reaction ofthe treated material with the treatment agent even after it has left thetreating means, a separate reaction chamber according to FIG. 2 isprovided in which certain accelerating reaction conditions may becreated and in which the material is transported without any contactwith the surroundings over a long stretch. The length of this stretchdepends on the kind and condition of the material, on the degree ofpre-drying by extraction rollers 30 corresponding to rollers 4 of FIG.1, and on the speed of movement of the material through the reactionzone. According to the invention, the reaction is controlled by thecreation of certain temperatures and humidities, for instance by theintroduction of water or solvent vapor and also by the introduction ofcertain chemicals in their vapor phase. The reaction chamber ispreferentially arranged in such a way that the material travels throughit vertically, since then the dyeing machine may be mounted directlyunderneath or above the chamber without the use of anydirection-changing rollers.

According to FIG. 2 the material leaves the dyeing machine and entersthe reaction chamber 31 which is situated immediately above orunderneath it, and the material is moved into the following drying zone(corresponding to chamber 7 of FIG. 1) only after, at the bottom end ofchamber 31 its direction is changed by a deflecting roller 32 and afurther pair of rollers 33. To the chamber 31 is connected a separaterecovery section which consists of fan 34, cooler 35 and heater 36, sothat air may circulate, according to arrows 37 and 38, through chamber31. For the establishment of a certain relative humidity in the chamber,the hygrometer 39 controls two valves 40 and 41 which are respectivelyconnected to a water-spray arrangement or a steam inlet. For theadjustment and constant maintenance of a certain temperature andsolvent-vapor concentration in the reaction chamber 31, a regulatingmeans 42 for the operation of the air heater or a regulating means 43for the cooling water supplied to the cooler 35 are controlled by adevice 44 in the air leaving the chamber, for instance a thermostat. Thevapor concentration in the chamber may also be controlled by twothermostats 45- and 46 which measure the temperature drop across thecooler 35. For the purpose of the introduction of further chemicalsanother pipe 47 with valves may be connected to the circuit.

The various means described enable an increase in the speed of reactionby the creation of favorable reaction conditions for the absorption ofthe chemical by the swelling fibers through temperature control, throughthe maintenance of certain relative vapor concentrations of oleophilicand hydrophilic media and by the addition of condensation acceleratorsin vapor form. The injection of steam or vapors of volatile chemicalsincreases the heat content of the drying air and the azeotropic dryingconditions speed up the drying process itself. Finally, the danger ofcondensation of the additive on the walls of the chamber may be avoidedby the introduction of the steam or vapors into the hot air streamcoming from the air heater ofthe air circuit.

The effective length of the reaction zone within chamber 31 may, withincertain limits, be altered by the adjustment of the deflecting rollers32 in the direction of arrow 48. In order to further increase theabsorptive capacity of the fibers for certain chemicals, the inventionprovides for a preconditioning zone through which the material has totravel prior to the entrance into the reaction chamber or into thetreating means and in which, according to fiber-content, it is treatedwith solvent or water vapor. By means of this primary swelling andwarming-up of the fibrous material, prior to its passage through thetreating means or dyeing machine, thesubsequent absorption of thechemicals is further accelerated and the reaction time is considerablyreduced. For this purpose in FIG. 3a preconditioning chamber 49 isarranged in front of the squeeze rollers 30, forming part of a paddingor impregnating unit, in which the material is passed through anatmosphere enriched with vapor (as schematically indicated at 53) and inwhich its direction is changed several times in the form of loops bydeflecting rollers 50. in its lower region the chamber is filled with aliquid which is evaporated by means of the heating coil 51. The entryand exit of the material may be protected from vapor loss throughcooling coils 52.

FIG. 4 shows a modified arrangement including a preconditioning chamber49' with deflecting rollers 50, heating means 51' and cooling means 52'interposed between rollers 30 and treatment chamber 31.

The speed of the drive for the material may be regulated in dependenceupon the solvent vapor concentration in one of the chambers, or independence upon the solvent content of the material itself. In theexample of FIG. 1 a device 54 for measuring solvent-vapor concentrationis provided in the outlet of the air from fresh-air chamber 9 which, inturn, can adjust by known means the speed of the transport means.

Since the material cannot be transported indefinitely in a direct linewithout contact with its surroundings for the purpose of undisturbedreaction with the applied chemicals, the disturbing effect of thedirection-changing rollers may be avoided by temperature-conditioning ofthe rollers through suitable cooling and/or heating means.

if elevated temperatures are required for the reaction of the appliedchemicals with the material, the possibility exists to provide a heatingarrangement, for instance infrared heaters, for the passing materials ina chamber which is attached to the drying chamber beyond the fresh-airzone. FIG. 5 shows schematically a washing and finishing machineaccording to the invention. Here the individual circuits are representedby lines in which an arrow indicates the direction of the flowingmedium. The necessary valves for the opening and closing of theindividual branch lines are indicated schematically by crosses. Theiradjustment, which is required to make and break the various connections,is ascertainable from the function of the individual components. I

Pumps 61 and 62 may continuously draw solvent from the containers 57 and58 and return same in a circuit (see direction of arrows) to thesecontainers. This can take place directly (with valve 66 opened, valve 64and 65 being closed) or by means of the filters 67 and 68 (valve 66closed, valves 64 and 65 opened) so that the solvent is freed from solidimpurities at the same time. In the same example the solvent is sprayedthrough jets 63 onto the material 1 from both sides and then passed intothe containers 57 and 58, the solvent flowing counter-current to thedirection of movement of the material from container 58 into container57. For the complete regeneration of the solvent fluid may be drained tostill 7 from filters 67 and 68 through the opening of valve 69. It thenenters the condenser 71 during the evaporation and is condensed there..The liquid collects in water separator 72 from where it flows to thestorage tank 73 for the clean solvent. From storage tank 73 the solventmay be directly passed to the jets 75 via valve 74. The latter jetsrinse the web 1, coming from container 58, once more with clean solvent.Via valve 76 the solvent from the storage tank 73 may also be introducedinto the pump circuit. The pumps 61 and 72 may be connected via pipes 93and 94 with the still 70, so that the solvent which has originally beentaken out of the storage tank 73 and which is used in the pump circuitmay be recycled for regeneration.

The material 1 leaving the housing 60 may be directed via the squeezingrollers 77 through a pre-drying zone 78 before it enters the actualpadding machine 79. In some instances it is also possible to forego theuse of this pre-drying zone 78 which therefore has been indicated onlyin dotted lines.

The padding machine 79 for the treatment with finishing chemicals may,in similar fashion, be connected with a pump circuit including a filterand a still, as previously described. For the sake of clarity this isindicated in FIG. 5 only by means of the two pipeline branches 80 and 81in which advantageously a strainer 82 is fitted into the suction side ofthe pump. A storage tank 83, filled with a concentrate of the chemicalto be deposited on the material 1, and a further storage tank 84, filledwith a working-strength solution of the treating liquor, are connectedvia pipe 85 to the vessel 86 of the padding machine 79. A closing means87 for the container 83, for instance a valve, is controlled by a device88 which measures the specific gravity of the liquid in container 86, sothat with falling concentration of the dissolved material in thetreating liquid valve 87 opens and closes again. In a similar manner avalve 89 is provided in the outlet of tank 84 which is controlled by asolvent-level gauge in container 86, for instance a float switch, sothat with rising or falling level the outlet from tank 84 is closed oropened. The two outlets 87 and 89 are electrically connected in such away that the valve 89 of the working-concentration tank 84 may be openedonly when the concentration of the chemical in the padding machine iscorrect and when the valve 87 of the concentrate tank 83 is closed. Theapparatus required for such measurement and control is well known andnot described in detail. The control functions are, therefore, shownonly schematically by means of the dotted lines 91 and 92.

The solvent which the material brings with it from the previous scouringstage unavoidably causes a dilution of the finishing liquid in thetreating means as well as an increase in the liquid quantity in thecontainer 86 of the treating means 79.

By means of the regulating method described above this danger is,however, eliminated. The described measures are equally valid when atwo-roller dyeing machine is used in which the treatment liquid iscontained between the two rollers.

oleophilic solvent it is advantageous to provide on the suction side ofthe pump an addition funnel or the like, so that the emulsification ofthe additive takes place within the pump. By means of an ultrasonicvibrator, an excellent emulsification or dispersion of solvent-insolublematerials may be achieved in the container which holds the treatmentliquor. By such ultrasonic vibrators, which are mounted in the chambers,the passing material is agitated and the reaction of the chemical on thematerial is improved.

As dyestufis, various classes of conventional texn'le dyes may be used,particularly those of the classes of nitro, azo, and anthrachinondyestuffs. In the first instance, so-called fat-soluble dyestuffs are tobe considered which have no acid or saltforming groups, are oftenreadily soluble in the organic carrier liquid and give full, deepcolors. Also dyestuffs which without being fat-soluble containoleophilic components, for instance higher molecular-weight hydrocarbonresidues, even if they contain acid or salt-forming groups as long asthese are not used in their usual form as water-soluble alkali salts,are suitable.

EXAMPLE 1 For the dyeing of a web of cloth of cellulose acetate, thedyestufi' represented by the formula below is dissolved in the ratio ofl 100 in carbon'tetrachloride:

In order to be able to emulsify hydrophilic substances in the gr mEXAMPLE 2 For the dyeing of cloth made of cellulose-2,5-acetate anazo-dyestufi of the following formula is dissolved in the ratio l intrichlorethylene:

The solution is used as described in Example 1 and aclear,

strong yellow color is achieved.

EXAMPLE 3 For the dyeing of cloth made of cellulose-tri-acetate, anazo-dyestuff of the following formula is dissolved in the ratio of l intrichlorethylene. The solution is clarified and then entered into thetreatment means. The cloth is passed through the bath at 8 meters perminute under the conditions mentioned in Example 1.

A strong yellow color is obtained. A similar effect may be obtained whenusing perchlorethylene as solvent with a fabric consisting ofcellulose-2,5-acetate. This yellow dyeing can also be carried out whenthe described method is applied to a cloth of regenerated cellulose(viscose).

([1 C1 C00 CzoHz =N\ N=N H-C 0 g We claim: 1. Apparatus for chemicallytreating fibrous material, comprising:

a substantially closed housing forming a plurality of adjoining chambersfor material to be treated, including a treatment chamber with an inletfor said material followed by a drying chamber with an outlet for saidmaterial;

guide means in said housing for successively directing a length of saidmaterial through said chambers;

supply means in said treatment chamber for applying a treatment fluid tosaid material;

conduit means forming a forced-circulation path for solvent vapors fromsaid treatment chamber, said path originating at a location of saidtreatment chamber proximal to said inlet and terminating at a locationof said drying chamber remote from said treatment chamber; and

blower means in said path for generating an air flow in said conduitmeans traversing said drying and treatment chambers in counter-currentto said material.

2. Apparatus as defined in claim 1 wherein said drying chamber issubdivided into a first compartment close to said treatment chamber andat least one further compartment beyond said first compartment, saidpath tenninating at said further compartment.

3. Apparatus as defined in claim 2 wherein said drying chamber includesa final compartment beyond said further compartment, said finalcompartment being provided with additional blower means forrecirculating air in a secondary path from a discharge side to anentrance side thereof.

4. Apparatus as defined in claim 3 wherein said guide means directs saidmaterial vertically downwardly through said final compartment, saidsecondary path starting at the bottom and ending at the top of saidfinal compartment.

5. Apparatus as defined in claim 3, further including solvent-recoverymeans in said secondary path.

6. Apparatus as defined in claim 1, further comprising cooling meansdisposed in said path downstream of said blower means.

7. Apparatus as defined in claim 1 wherein said treatment chamber isprovided with further conduit means forming a secondary air path from apoint of said treatment chamber near said inlet to a point thereofproximal to said drying chamber, said supply means being disposedbetween said points, said secondary air path including additional blowermeans for circulating vapor-laden air therethrough.

8. Apparatus as defined in claim 7 wherein said further conduit means isprovided with hygroscopically controlled means for admitting moistureinto said secondary air path.

9. Apparatus as defined in claim 7 wherein said secondary air pathfurther includes heating means downstream of said additional blowermeans.

10. Apparatus as defined in claim 7 wherein said supply means comprisestwo sets of jets on opposite sides of the line of travel of saidmaterial through said treatment chamber, said forced-circulation pathand said secondary air path having intake ports located in saidtreatment chamber at said opposite sides ahead of said sets of jets.

11. Apparatus as defined in claim 10 wherein said secondary air path hasdischarge ports entering said treatment chamber at said opposite sidesbeyond said sets of jets.

12. Apparatus as defined in claim 1 wherein said chambers include areaction chamber between said treatment and drying chambers and a sourceof moisture for said reaction chamber.

13. Apparatus as defined in claim 12 wherein said source includes an airduct communicating with said reaction chamber at an entrance side and anexit side for said material and further blower means in said air ductfor circulating air therethrough from said entrance side to said exitside, said duct having an inlet connection for aqueous fluid.

14. Apparatus as defined in claim 13, further comprising hygroscopicallycontrolled means in said duct for regulating the moisture content ofsaid reaction chamber.

15. Apparatus as defined in claim 13 wherein said chambers include apreconditioning chamber, immediately ahead of said reaction chamber,provided with temperature-control means.

16. Apparatus as defined in claim 15 wherein said guide means includes apair of squeeze rollers engaging said material at an end of saidpreconditioning chamber.

17. Apparatus as defined in claim 1 wherein said chambers extendvertically in said housing, said guide means comprising a top deflectorand a bottom deflector in each chamber engaging said material forvertical motion in otherwise unsupported manner between said deflectors.

18. Apparatus as defined in claim 17 wherein at least one of saidchambers is provided with an individual duct, communicating therewith atthe top and the bottom, and with additional blower means in said ductfor circulating air therethrough and through the chamber in counterfiowto said material.

2. Apparatus as defined in claim 1 wherein said drying chamber issubdivided into a first compartment close to said treatment chamber andat least one further compartment beyond said first compartment, saidpath terminating at said further compartment.
 3. Apparatus as defined inclaim 2 wherein said drying chamber includes a final compartment beyondsaid further compartment, said final compartment being provided withadditional blower means for recirculating air in a secondary path from adischarge side to an entrance side thereof.
 4. Apparatus as defined inclaim 3 wherein said guide means directs said material verticallydownwardly through said final compartment, said secondary path startingat the bottom and ending at the top of said final compartment. 5.Apparatus as defined in claim 3, further including solvent-recoverymeans in said secondary path.
 6. Apparatus as defined in claim 1,further comprising cooling means disposed in said path downstream ofsaid blower means.
 7. Apparatus as defined in claim 1 wherein saidtreatment chamber is provided with further conduit means forming asecondary air path from a point of said treatment chamber near saidinlet to a point thereof proximal to said drying chamber, said supplymeans being disposed between said points, said secondary air pathincluding additional blower means for circulating vapor-laden airtherethrough.
 8. Apparatus as defined in claim 7 wherein said furtherconduit means is provided with hygroscopically controlled means foradmitting moisture into said secondary air path.
 9. Apparatus as definedin claim 7 wherein said secondary air path further includes heatingmeans downstream of said additional blower means.
 10. Apparatus asdefined in claim 7 wherein said supply means comprises two sets of jetson opposite sides of the line of travel of said material through saidtreatment chamber, said forced-circulation path and said secondary airpath having intake ports located in said treatment chamber at saidopposite sides ahead of said sets of jets.
 11. Apparatus as defined inclaim 10 wherein said secondary air path has discharge ports enteringsaid treatment chamber at said opposite sides beyond said sets of jets.12. Apparatus as defined in claim 1 wherein said chambers include areaction chamber between said treatment and drying chambers and a sourceof moisture for said reaction chamber.
 13. Apparatus as defined in claim12 wherein said source includes an air duct communiCating with saidreaction chamber at an entrance side and an exit side for said materialand further blower means in said air duct for circulating airtherethrough from said entrance side to said exit side, said duct havingan inlet connection for aqueous fluid.
 14. Apparatus as defined in claim13, further comprising hygroscopically controlled means in said duct forregulating the moisture content of said reaction chamber.
 15. Apparatusas defined in claim 13 wherein said chambers include a preconditioningchamber, immediately ahead of said reaction chamber, provided withtemperature-control means.
 16. Apparatus as defined in claim 15 whereinsaid guide means includes a pair of squeeze rollers engaging saidmaterial at an end of said preconditioning chamber.
 17. Apparatus asdefined in claim 1 wherein said chambers extend vertically in saidhousing, said guide means comprising a top deflector and a bottomdeflector in each chamber engaging said material for vertical motion inotherwise unsupported manner between said deflectors.
 18. Apparatus asdefined in claim 17 wherein at least one of said chambers is providedwith an individual duct, communicating therewith at the top and thebottom, and with additional blower means in said duct for circulatingair therethrough and through the chamber in counterflow to saidmaterial.